Decolorization of lubricating oils



Jan. 5, 1932. T. T. GRAY DECOLORIZATION OF LUBRICATING OILS Filed Feb. 7.. 1928 Patented Jan. 5, `1932 UNITED STATES PATENT OFFICE f THOMAS T. GRAY, 0F ELIZABETH, NEW JERSEY, ASSIGNOR TO THE GRAY PROCESSES CORPORATION, 0F NEWARK, NEW JERSEY, A CORPORATION 0F DELAWARE DECOLORIZATION OF LUBRICATING OILS Application filed February 7, 1928. Serial No. 252,626.

This invention relates to the decolorizing of petroleum fractionsv suitable for use as lubricating oils. Lubricating oils are usually purified for decolorizing purposes and lremoval of asphaltic material by treatment with-sulphuric acid, by filtration of the oil in liquid phase through fullers earth or by contact of the oil inliquid phase with fullers earth or other clays. It has been suggested in the past that the filtration through ullers earth be combined with a distillation step by passing lubricating oil in vapor phase through fullers earth. Heretofore this has not been satisfactorily accomplished.

An object of this invention is the process of decolorizing lubricating oils-in which the decolorization is accomplished by passing the lubricating oil in vapor phase through fullers earth or the like.

In previous attempts to decolorize lubricating oil in vapor phase by contact `with fullers earth poor decolorization has resulted and the yield per ton of catalyst has been low. These results probably were due to lack' of proper time of contact between the vapors and the fullers earth and the fact that it was attempted to prevent condensation of the vapors being filtered. I have discovered that greatly improved results can be obtained by passing the oil vapors through a substantial bed of decolorizing material suchfor example as fullers earth or the like, providing that lubricating oil in liquid phase is simultaneously passed through the decolorizing material, the liquid lubricating 011 acting as a washing agent to remove coloring matter from the decolorizing material. `It is well known that when fullers earth or other similar material is used to decolorize lubricating oil, highly colored matter ad? hered thereto and is not removed by the o1l being treated. This soon results in the devitalization of the treating material. The coloring material is however considerably more soluble in hot oil, say from 300o to 400 F. or higher than in cold oil and can be removed from the ullers earth to a substantial extent by passing hot oil through it.

The lubricating oil in liquid Aphase for washing out the coloring matter from the decolorizing material may be obtained in any one of a number of different ways. The conditions under which the vapor passes through the treating material may be so regulated that a portion of the vapors condenses therein or means may be provided for condensing a portion of vapors before they reach the treating material. This latter v operation may be accomplished by spraying oil into the vapors or by arranging a cooling coil Within the vapor stream. Irrespective of the method in which the lubricating oil for the washing operation is obtained, a greatly increased life of the decolorizing material and improved decolorization is obtained by washing out the coloring matter.

I prefer to pass the vapors downwardly through the decolorizing material so that the vapor stream aids in removing the condensate and coloring matter from the treating material. It'- desired, the vapors can be passed upwardly through the treating material and in such event it is desirable to provide a liquid separator for separating from the vapors any liquid that may be carried over with` them.

This invention may be applied to any type y ot distilling apparatus producing lubricati ing oil distillates including steam and vacuum distilling apparatus. y The decolorized distillate produced may be a finished product or may be a product to be subjected to further treatment which may include further distillation with or without further decolorization.

Other objects, novel features and advantages of this invention will be apparent from the following specification, wherein- Figs. 1, 2 and 3 are vertical sections through different types of apparatus suitable for use in the process.

In Fig. l, 10 designates a tower within which is provided an annular partition 11 which forms with the wall of the tower 10 an annular chamber 12. The partition 11 terminates short of the top of the tower 10 so that thev central chamber 13 is in communication with the annular chamber 12. A pipe 14 controlled by a valve 15 leads into the lower portion of the annular chamber 12 and it is by this pipe that vaporized lubri` eating oil is introduced into the tower for treatment. Within the chamber 13 and near the bottom thereof is provided a funnel-like perforated shelf 16 terminating yin a discharge spout 17 controlled by a valve 18. A pipe 19 controlled by valve 2O leads from the chamber 13 at a point below the shelf 16 and provides means for discharging treated vaporized lubricating oil from the apparatus. Trapped pipes 21 and 22 lead from the bottoms of the chambers 12 and 13 respectively for the purpose of removing therefrom any liquids collecting in these chambers.A The perforated shelf 16 is covered with a layer of mineral wool or the like and the inner chamber 13is charged with decolorizing material such for example as fullers earth or the like and which is designated by the reference character 24. The mineral wool prevents the decolorizing material sifting through the perforations in the shelf 16 but permits free passage of fluids. In the upper part of the tower there is provided a spray 25 by means of which liquid may be introduced into the treating tower and there is also provided a coil 26 through which a cooling medium may be circulated.

In the apparatus disclosed in Fig. 1 vaporized lubricating oil is admitted to the annular chamber 12 through the pipe 14 and is thus brought, into heat exchange relationship to the decolorizing material 24. There will be some condensation of lubricating oil in the annular chamber which condensate will be removed by the pipe 21. The vapors flow over the top edge of the partition 11 and downwardly through the treating material 24 through the perforations in the shelf 16 and are discharged through the pipe 19. The circulation of the vapors around the treating material prior to contact therewith serves to heat the latter nearly to the temperature of the vapors under treatment. There will, however,- be some condensation of the lubricating oil vapor in the central chamber 13 due to the fact that the decolorizing material is at notquite as high teinperature as the vapor. The condensate thlls formed is substantially at the same tempera` ture as the vapors and serves to wash out of the decolorizing material any coloring Inat-y ter deposited therein from the vapors. This condensate together with the coloring matter collects in the bottom of the treating tower and is removed by the pipe 22. Should the condensate formed in the manner above described be insufficient to wash out the coloring matter, such condensate may be increased by means either of the spray 25 or the cooling coil 26. Previously treated lubricating oil may be sprayed into the vapor by means of the spray 25'and the heat dissipated by the vapors in heating such added oil will cause further condensation; also the circulation of the cooling fluid through the coil 26 will cause additional condensation. Either or both the spray and the cooling coil may be used to supplement the condensate ordinarily forming within the chamber 13 in the event that such condensate is insufficient thoroughly to wash out the coloring matter from the decolorizing material.`

Referring now to Fig. 2, 30 designates the treating tower which is of the single shell vtype and is provided with a layer of insulation 31. A funnel-like perforated shelf 32 is provided within the tower 3() and terminates in a discharge spout 33 controlled by a valve 34. A pipe 35 controlled by a valve 36 constitutes the inlet to the tower and through through. A trapped pipe 41 leads from the bottom of the tower for removing liquids collecting therein. In the top of the tower there is provided a spray 42 and a coollng coil 43.

The operation with the apparatus disclosed in Fig. 2 is quite similar to that described in connection with Fig. 1. The vapors to be treated enter by the pipe 35, pass through the treating material 4() and are discharged through the pipe 37. Radiation of heat from the tower wall keeps the treating material at a temperature slightly below that of the vapor being treated so that there is some condensation in the treating material. The radiation from the tower wall may be insufficient due to the insulation 31 to produce sufficient condensate to wash out all the coloring matter. Such condensate may be supplemented as previously described by the spray 42 or the cooling coil 43. The flow of vapors through the treating material is in the same direction as the flow of the condensate so that the vapors accelerate the action of the condensate to a certain extent.

In Fig. 3, 50 is the treating tower and 51 is the layer offinsulation. 52 is the funnellike'perforated shelf terminating in a discharge spout 53 controlled by valve 54. 55 is the inlet pipe for the vapors to be treated and is controlled by a valve 56. This inlet. is arranged below the shelf 52 so that the vapors are caused to travel upwardly through the tower. 57 is the outlet pipe which is arranged near the top of the tower and leads into the vapor separator 58,.J the outlet 59 of which is controlled by a valve 60. A layer of mineral wool 61 is provided on the shelf 52 for the purpose of making the shelf impervious to solids but pervious to fluids. A supply of decolorizing material 62 is arranged within the tower 50. A trapped pipe 63 leads from the bottoin of the tower 50 for the purpose .of removing any liquids collecting therein. In the upper part of the tower is provided a spra 64 andv a cooling coil 65. The o eration o this apparatus is similar to that disclosed in Fig. 2 except that the vapor to be treated passes upwardly through the decolorizing-material. Under such clrcumstances the treated vapor may carry off entrained liquid and for this reason the treated vapor is led through the separator 58 for the purpose of removing from it any entrained liquid. v

In each instance vaporized lubricating oil and heated liquid lubricating oil are passed through a substantial bed of decolorizing material. .The decolorizing materialremoves the coloring matter from the vaporized lubricating oil, such coloring matter being deposited in the decolorizing material. The hot liquid lubricating oil dissolves the coloring matter thus deposited and washes the same out of the decolorizing material. A certain amount of condensate is produced in the treating mate- .'rial due to loss of heat byA radiation. The

. washin condensate thus formed may or may not be suiicient. Additional condensate may be provided either by spraying in liquid lubricating oil or by vpassing cooling iuid through the coil 26 or if necessary by use of both. The essential steps in the process comprise passing vaporized lubricating oil through decolorizing material and simultaneously passing hot lubricating oil in liquid form throu h the decolorizing material for preventin tion thereof and it is comparative y unimportant as tothe articular manner in which the fluid) is obtained. Although the ways o obtaining the washing fluid above described are preferred, yet itis to be understood that there are various other ways of obtaining the washin fiuid. The invention is not limited to any orm .of distillation apparatus and the decolorized distillate treated may be a finished product or it may be a product which may need additional treatment before it is finished.

It is of course apparent that the process, as well as the apparatus, above described may be varied without in any way departing from the spirit of the invention as defined in the appended claims.

I claim as my invention:

1. The process of decolorizing petroleum fractions suitable for use as lubricating oil,

which'comprises passing .the same invapor phase through a bed of solid adsorptive decolorizing material and simultaneously utilizing lubricating oil of substantially the same composition as the fraction being treated and in liquid phase to wash outI from said deevitaliza- 3. The process of decolorizing petroleum y fractions suitable for use' as lubricating oil which comprises passing the samein vapor phase through a bed of solid adsorptive material and simultaneously passing lubricating oil of substantially the same composition as the petroleum fractions being treated and in liquid phase through' said de-colorizing material in the directionof flow of the vapor to wash out from said decolorizing material coloring matter deposited therein.

' 4. The process of decolorizing petroleum fractions suitable for use as lubricating oil which comprises passing thesame in vapor phase through a bedy of solid adsorptive decolorizing material contained in a closed zone, causing condensation above the bottom of said bed of a portion of the petroleum fractions being treated in said zone and utilizing 'the condensate thus obtained to wash out from said decolorizing material coloring matter'deposited therein. v

5. The process of decolorizing petroleum fractions suitable for use as lubricating oil, which comprises passing the same in vapor phase downwardly through a bed of solid adsorptive decolorizing material contained in a closed zone, condensing a portion of the petroleum fractions being treated above the bottom of said bed of decolorizing material in said zone and causing said condensate to percolate through said decolorizing material for removing therefrom coloring matter deposited therein.

6. The process of decolorizing petroleum fractions suitable for use as lubricating oil, which comprises passing the same in vapor phase through a bed of solid adsorptive decolorizing material, simultaneously passing condensate of said petroleum fractions through said material, the condensate being maintained substantially at the temperature.

name to this specification. l

THOMAS Tl GRAY.

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